Physcion-8-O-β-D-monoglucoside protects hepatocytes from TNF-α-mediated apoptosis by suppressing the PI3K/AKT/NF-κB signaling pathway

Physcion-8-O-β-D-monoglucoside (PMG) is one of the active ingredients of Radix et Rhizoma Rhei, which has been used for treating liver diseases for hundreds of years in China. However, the hepatoprotective effects of PMG remain poorly understood. This study aimed to investigate the mechanism of the protection effects of PMG on tumor necrosis factor-α (TNF-α)-induced hepatotoxicity. We developed both in vitro and in vivo models of liver injury to assess the protective effects of PMG against TNF-α-induced hepatotoxicity. The in vitro model employed TNF-α/actinomycin D in AML-12 cells, while the in vivo model utilized intraperitoneal injection of carbon tetrachloride (CCl4) in mice. Interactions of PMG and TNFR1 (the receptor of TNF-α) were explored by molecular docking. AAV resuspension was administered before PMG treatment via intravenous injection to overexpress TNF-α in the CCl4-induced mice. The effects of PMG on liver injury were assessed using CCK-8 assay, AST/ALT level measurement, and HE staining. Cell apoptosis was detected through Hoechst staining, TUNEL staining, and the levels of cleaved caspase-3. mRNA expression of TNF-α and IL-6 was quantified using real-time PCR, while the related proteins were detected by Western blotting. The protein localization of TNF-α was visualized by immunofluorescence assays. PMG effectively protected against hepatotoxicity in vitro and in vivo by restoring cell survival, decreasing AST, ALT, and reducing apoptosis. TNF-α overexpression counteracted the hepatoprotective effects of PMG, ‌thereby‌ attenuating its regulatory impacts on apoptosis and the ‌dysregulation‌ of the PI3K/AKT/NF-κB signaling pathway. ‌Notably‌, PMG ameliorated hepatotoxicity by restoring the TNF-α-mediated apoptosis signaling pathway, ‌supporting‌ its potential as a ‌novel therapeutic‌ for acute liver injury.